Telematics units have been used with vehicles to provide a variety of services to subscribers of these services. For instance, a telematics service subscriber can receive customized GPS navigation directions, vehicle tracking in case of a theft, emergency services in case of air bag activation, unlocking of vehicle doors, slowing and disabling a vehicle by a law enforcement officer, etc. Furthermore, the subscriber may receive a detailed diagnostic report through a service website or as an email describing the operating condition of the vehicle. This report may also suggest some urgent or preventive services needed.